package com.ten.jinxiancun.utils;

import org.apache.shiro.codec.Hex;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Random;

public class MD5Util {
	/**
	 * 普通MD5加密<br>
	 * 
	 * 
	 * 
	 * @param input
	 * 
	 * @return
	 * 
	 */

	public static String MD5(String input) {

		MessageDigest md5 = null;

		try {

			md5 = MessageDigest.getInstance("MD5");

		} catch (NoSuchAlgorithmException e) {

			return "check jdk";

		} catch (Exception e) {

			e.printStackTrace();

			return "";

		}

		char[] charArray = input.toCharArray();

		byte[] byteArray = new byte[charArray.length];
		for (int i = 0; i < charArray.length; i++)

			byteArray[i] = (byte) charArray[i];

		byte[] md5Bytes = md5.digest(byteArray);

		StringBuffer hexValue = new StringBuffer();

		for (int i = 0; i < md5Bytes.length; i++) {

			int val = ((int) md5Bytes[i]) & 0xff;

			if (val < 16)

				hexValue.append("0");

			hexValue.append(Integer.toHexString(val));

		}

		return hexValue.toString();
	}

	/**
	 * 
	 * 加盐MD5加密<br>
	 *
	 * 
	 * 
	 * @param password
	 * 
	 * @return
	 * 
	 */

	public static String getMD5(String password) {

		Random r = new Random();

		StringBuilder sb = new StringBuilder(16);

		sb.append(r.nextInt(99999999)).append(r.nextInt(99999999));

		int len = sb.length();

		if (len < 16) {

			for (int i = 0; i < 16 - len; i++) {

				sb.append("0");

			}

		}

		String salt = sb.toString();

		password = md5Hex(password + salt);

		char[] cs = new char[48];

		for (int i = 0; i < 48; i += 3) {

			cs[i] = password.charAt(i / 3 * 2);

			char c = salt.charAt(i / 3);

			cs[i + 1] = c;

			cs[i + 2] = password.charAt(i / 3 * 2 + 1);

		}

		return new String(cs);

	}

	/**
	 * 
	 * 校验加盐后是否和原文一致<br>
	 * 
	 * 
	 * 
	 * @param password
	 * 
	 * @param md5
	 * 
	 * @return
	 * 
	 */

	public static boolean verify(String password, String md5) {

		try {
			char[] cs1 = new char[32];

			char[] cs2 = new char[16];

			for (int i = 0; i < 48; i += 3) {

				cs1[i / 3 * 2] = md5.charAt(i);

				cs1[i / 3 * 2 + 1] = md5.charAt(i + 2);

				cs2[i / 3] = md5.charAt(i + 1);

			}

			String salt = new String(cs2);

			return md5Hex(password + salt).equals(new String(cs1));

		} catch (Exception e) {
			return false;

		}
	}

	/**
	 * 
	 * 获取十六进制字符串形式的MD5摘要
	 * 
	 */

	private static String md5Hex(String src) {

		try {

			MessageDigest md5 = MessageDigest.getInstance("MD5");

			byte[] bs = md5.digest(src.getBytes());

			return new String(new Hex().encode(bs));

		} catch (Exception e) {

			return null;

		}

	}
}
